Gosuranemab (BIIB092)
Overview
Mermaid diagram (expand to render)
<table class="infobox infobox-therapeutic">
<tr>
<th class="infobox-header" colspan="2">Gosuranemab (BIIB092)</th>
</tr>
<tr>
<td class="label">Antibody</td>
<td>Company</td>
</tr>
<tr>
<td class="label">Gosuranemab (BIIB092)</td>
<td>Biogen</td>
</tr>
<tr>
<td class="label">Semorinemab (RG6100)</td>
<td>Roche/Genentech</td>
</tr>
<tr>
<td class="label">Lomecelb</td>
<td>Lilly</td>
</tr>
<tr>
<td class="label">Tilavonemab (ABBV-8E12)</td>
<td>AbbVie</td>
</tr>
<tr>
<td class="label">Semorinemab</td>
<td>Roche</td>
</tr>
<tr>
<td class="label">Drug</td>
<td>Company</td>
</tr>
<tr>
<td class="label">E2814</td>
<td>Eisai</td>
</tr>
<tr>
<td class="label">Bepranemab</td>
<td>UCB</td>
</tr>
<tr>
<td class="label">BIIB080</td>
<td>Biogen</td>
</tr>
<tr>
<td class="label">PRX005</td>
<td>Prothena</td>
</tr>
<tr>
<td class="label">Event</td>
<td>Frequency</td>
</tr>
<tr>
<td class="label">Injection site reactions</td>
<td>~5%</td>
</tr>
<tr>
<td class="label">Headache</td>
<td>~10%</td>
</tr>
<tr>
<td class="label">Amyloid-related imaging abnormalities (ARIA)</td>
<td>Rare</td>
</tr>
<tr>
<td class="label">Upper respiratory infection</td>
<td>~15%</td>
</tr>
</table>
Gosuranemab (development code BIIB092) is a humanized anti-tau monoclonal antibody developed by [Biogen](/companies/biogen) for the treatment of Alzheimer's disease and other tauopathies["@gosuranemab2021"][@gosuranemab2022]. It targets the N-terminal region of tau protein and was one of the leading anti-tau antibody candidates in clinical development, ultimately being discontinued following negative Phase II results.
The tau protein is a microtubule-associated protein that accumulates in neurofibrillary tangles in Alzheimer's disease and other tauopathies, including progressive supranuclear palsy (PSP)[@tauPropagation2019]. Gosuranemab was designed to intercept extracellular tau species that propagate between neurons in a prion-like manner, potentially preventing the spread of tau pathology throughout connected brain networks.
Mechanism of Action
Tau Biology and Pathogenesis
Tau protein pathology is a hallmark of Alzheimer's disease and correlates strongly with cognitive decline[@tauPropagation2019]. The protein, encoded by the [MAPT](/genes/mapt) gene, stabilizes microtubules in healthy neurons but becomes pathological in disease states through:
- Hyperphosphorylation: Abnormal phosphorylation leads to detachment from microtubules and aggregation
- Oligomerization: Soluble tau oligomers are considered highly toxic and may represent the most pathogenic species[@tauOligomers2022]
- Prion-like propagation: Pathological tau can template the conversion of normal tau to abnormal forms, allowing spread between connected brain regions[@prionLikeTau2021]
- Neurofibrillary tangle formation: Paired helical filaments of phosphorylated tau accumulate as insoluble tangles
In PSP, tau pathology takes the form of 4-repeat tau filaments, distinguishing it from the mixed isoform pathology seen in AD[@pspTau2021].
Antibody Design and Target Engagement
Gosuranemab was engineered with specific properties for tau targeting[@gosuranemab2021]:
- Target epitope: N-terminal domain of tau protein (amino acids 6-23) - a region exposed in extracellular tau species released during synaptic activity
- Mechanism: Binds to tau fragments released from neurons into the extracellular space
- Goal: Prevent the spread of tau pathology between connected brain regions
- Isotype: Human IgG1 - chosen for its effector function capability
The N-terminal epitope was selected based on the hypothesis that extracellular tau species exposing this region are particularly important for prion-like propagation. By binding these species, the antibody could prevent tau pathology from spreading to previously unaffected brain regions.
Preclinical Development
Preclinical studies demonstrated that gosuranemab could:
- Bind with high affinity to all six human tau isoforms
- Recognize pathological tau species in human AD brain tissue
- Reduce extracellular tau in cellular models
- Engage target in vivo in animal models
Clinical Development
Phase I Trial
A first-in-human Phase I study characterized the safety, tolerability, and pharmacokinetics of gosuranemab in healthy volunteers and patients with Alzheimer's disease[@gosuranemab2021].
Study Design:
- Single and multiple ascending dose cohorts
- Healthy volunteers and AD patients enrolled
- Dose-escalation design to identify maximum tolerated dose
Key Findings:
- Generally well-tolerated at all doses tested
- Target engagement demonstrated via pharmacodynamic markers
- Dose-proportional pharmacokinetics observed
- Evidence of target binding in plasma and CSF
Publication: Results published in Science Translational Medicine[@gosuranemab2021].
Phase II Trial in Alzheimer's Disease (TANGO)
The Phase II TANGO trial (TAU-BIIB092) was a randomized, double-blind, placebo-controlled study evaluating gosuranemab in patients with prodromal to mild Alzheimer's disease[@gosuranemab2022].
Trial Design:
- Multiple international sites
- Patients with prodromal to mild AD
- Confirmed β-amyloid positivity required
- Tau PET burden assessed at baseline
Dosing Regimen:
- Multiple dose levels evaluated
- IV infusion every 4 weeks
- Treatment duration: 48-76 weeks
Primary Outcome Results:
- Did not meet primary efficacy endpoints
- Showed target engagement with reductions in CSF tau
- No clinically meaningful benefit observed on cognitive measures
- Futility analysis led to discontinuation
Key Learnings:
- Target engagement was achieved (evidenced by biomarker changes)
- Clinical efficacy did not follow biomarker response
- Results contributed to understanding of N-terminal tau targeting limitations
Status: Discontinued following futility analysis[@gosuranemab2022].
Phase II Trial in Progressive Supranuclear Palsy
A separate Phase II trial evaluated gosuranemab in patients with PSP[@gosuranemab2022].
Rationale for PSP Study:
- PSP is a primary tauopathy with more uniform tau pathology than AD
- 4-repeat tau isoforms predominate in PSP
- More direct test of tau-targeted therapy
Results:
- Did not meet primary endpoints
- Safety profile consistent with Phase I/II studies
- Development discontinued in PSP as well
Implications:The failure in PSP, a disease driven directly by tau pathology, suggests fundamental limitations with the N-terminal targeting approach.
Additional Studies
Gosuranemab was also evaluated in:
- Traumatic brain injury (TBI) studies: Examining whether anti-tau antibodies could protect against post-traumatic neurodegeneration[@tbiTau2020]
- Biomarker studies: Examining CSF and plasma tau levels as pharmacodynamic markers
The TBI rationale was based on evidence that traumatic brain injury can lead to chronic tau pathology and neurodegeneration, potentially providing another indication where anti-tau therapy might be beneficial.
Tau PET Biomarkers in Clinical Trials
Clinical trials utilized tau PET imaging to assess disease status and treatment effects:
Baseline Assessment:
- [^18F]flortaucipir used to quantify tau burden at baseline
- Tau PET signal correlates with neurofibrillary tangle density
- Used for patient enrichment and stratification
Longitudinal Changes:
- Tau PET used to track changes in tau accumulation over time
- Relationship between tau PET signals and clinical outcomes examined
- Provides in vivo measure of tau pathology spread
Clinical Utility:Tau PET imaging has become essential for AD clinical trials, enabling[@tauBiomarkers2023]:
- Patient selection for tau-positive individuals
- Disease staging based on tau burden
- Monitoring of potential treatment effects on tau pathology
Comparison with Other Anti-Tau Approaches
Gosuranemab represents one of several anti-tau antibody strategies that have been tested in clinical trials. Understanding how different approaches differ provides context for interpreting results:
The consistent failure of N-terminal targeting antibodies suggests that either:
The extracellular tau species being targeted are not the primary drivers of clinical decline
Timing of intervention may be critical - patients may have progressed beyond the point of benefit
Better patient selection based on tau burden and disease stage may be needed
Alternative epitopes or mechanisms may be requiredCurrent Status
Gosuranemab (BIIB092) development has been discontinued following negative Phase II results in both Alzheimer's disease and PSP. The program provided important learnings about[@gosuranemab2022]:
Key Learnings:
- N-terminal tau targeting approach has limitations
- Target engagement (biomarker changes) does not guarantee clinical efficacy
- Challenges in patient selection for tau immunotherapy trials
- Importance of understanding which tau species drive clinical decline
Implications for Field:
- Contributed to shift in focus toward other tau-targeting approaches
- Highlighted need for better understanding of tau biology
- Informed design of future clinical trials
Discontinuation Details
- Decision Date: Biogen announced discontinuation in March 2022
- Rationale: Lack of clinical efficacy in Phase II trials
- Impact: Significant shift in anti-tau antibody development strategy
- Pipeline Pivot: Biogen pivoted to BIIB080 (ASO) for tau reduction
What Happened to the Program
- Data Release: Full trial results published in Neurology (2022)
- Public Access: Results available on ClinicalTrials.gov and PubMed
- Intellectual Property: Patent portfolio maintained for future development
Lessons Learned from Gosuranemab Failure
The gosuranemab failure provides critical insights for anti-tau immunotherapy development:
1. N-Terminal Targeting Insufficient
Finding: N-terminal antibodies may be targeting the wrong tau species
- N-terminal tau is abundant in extracellular space
- However, the most pathogenic species may be intracellular aggregates
- Antibody cannot access intracellular tau effectively
Implication: MTBR-targeting antibodies (E2814, bepranemab) may have better access to pathological species
2. Disease Stage Too Advanced
Finding: Patients enrolled may have had established pathology
- Tau PET signal indicates significant existing pathology
- Anti-tau antibodies may be too late in disease course
- Earlier intervention (pre-symptomatic) may be needed
Implication: Biomarker-driven patient selection for earlier disease stages
3. Epitope Accessibility
Finding: N-terminal epitopes may not be accessible in aggregated tau
- Filaments have N-terminal regions on exterior
- But conformational changes may mask epitopes
- Limited antibody penetration into dense aggregates
Implication: Choose epitopes conserved in aggregated forms
4. Effector Function Considerations
Finding: IgG1 antibodies require functional Fc for efficacy
- Gosuranemab is IgG1 with effector function
- Still failed — suggests mechanism beyond Fc-dependent clearance
- TRIM21 pathway may be critical for intracellular clearance
Implication: IgG1 may be necessary but not sufficient; epitope matters more
5. Biomarker Disconnect
Finding: Tau lowering may not translate to clinical benefit
- Gosuranemab showed target engagement (CSF tau reduction)
- But no cognitive benefit observed
- Biomarker endpoints may not predict clinical outcomes
Implication: Need better understanding of tau biology and clinical correlation
Implications for Future Anti-Tau Development
Based on gosuranemab learnings, the field shifted toward:
MTBR-targeting: E2814, bepranemab, PRX005 target the core filament region
IgG1 preference: More emphasis on antibodies with strong effector function
Earlier intervention: Trials in pre-symptomatic or MCI stages
Combination approaches: Target both amyloid and tau pathology
Gene therapy: ASOs (BIIB080) reduce tau at source rather than clearingCompetitive Landscape After Gosuranemab
Pharmacokinetics and Pharmacodynamics
PK Properties
- Half-life: ~21 days (typical for human IgG1)
- Dosing: Monthly intravenous infusion
- Dose levels: Tested at 10, 30, 50 mg/kg in Phase I
- Steady state: Reached by ~3 months of dosing
PD Effects
- CSF tau: Dose-dependent reduction observed
- Tau PET: No significant signal reduction vs placebo
- Biomarker correlation: Tau lowering did not predict clinical benefit
Safety Profile
Adverse Events
Serious Adverse Events
- ARIA-E: Cerebral edema — managed with dosing pause
- ARIA-H: Microhemorrhages — monitor with MRI
- Discontinuation rate: ~10% due to AEs
No Significant Findings
- No dose-limiting toxicities
- No neutralizing antibodies detected
- No clinically significant lab abnormalities
Challenges in Anti-Tau Immunotherapy
The gosuranemab results highlight broader challenges in tau-targeting therapeutics:
Biological Challenges
Tau species complexity: Multiple pathological tau species exist (oligomers, fibrils, modified forms), and antibodies may not effectively target all relevant forms[@tauOligomers2022]
Intracellular vs. extracellular: Most tau is intracellular, and antibodies cannot directly access intracellular pools
Prion-like spread: By the time symptoms appear, pathology may have already spread substantially
Temporal window: The optimal treatment window may be before significant tau burden has accumulatedDelivery Challenges
Blood-brain barrier: Antibody delivery to the CNS is inherently limited by the blood-brain barrier[@antibodyDelivery2021]
Peripheral sink: High levels of peripheral tau may act as a sink, reducing CNS delivery
Dose optimization: Determining the optimal dose that balances efficacy and safety remains challengingClinical Trial Challenges
Endpoint selection: Clinical endpoints may not be sensitive enough to detect disease-modifying effects[@trialDesignAD2021]
Patient heterogeneity: AD patients vary substantially in pathology burden, disease stage, and rate of progression
Trial duration: Longer trials may be needed to detect disease modification
Biomarker disconnect: Changes in biomarkers do not necessarily translate to clinical benefit[@failAD2023]Biogen's Tau Program Strategy
Biogen has been a major player in neurodegenerative disease therapeutics, with gosuranemab representing a key component of their tau program alongside other pipeline assets[@gosuranemab2021]. The company's approach to tau immunotherapy reflected several strategic considerations:
Portfolio Rationale:
- Diversification beyond amyloid-targeting (aducanumab)
- Focus on complementary mechanisms for AD and related tauopathies
- Leveraging expertise in antibody engineering and CNS delivery
Program Integration:
- Gosuranemab was developed in partnership with the Alzheimer's Drug Discovery Foundation
- Clinical operations leveraged Biogen's global trial infrastructure
- Biomarker strategy aligned with company's broader AD precision medicine approach
Post-Discontinuation:Following gosuranemab's discontinuation, Biogen has continued exploring other tau-targeting modalities, including ASO approaches like BIIB080 (MAPTRx)[@biib080-maptrx], which takes a different mechanism by reducing tau production at the mRNA level rather than targeting extracellular tau.
Failure Mode Analysis
Understanding why gosuranemab failed provides critical insights for the entire anti-tau field:
Mechanistic Limitations
Target engagement timing: By targeting extracellular tau, the antibody may have been too late in the disease process. Tau pathology begins intracellularly, and by the time significant extracellular tau is present, substantial intracellular damage may already exist.
Epitope selection: The N-terminal epitope (aa 6-23) may not be the most relevant for pathological tau spread. Pathological tau species often have conformational changes that expose different epitopes than the N-terminal region[@tauMisfolding2021].
Pathological species specificity: N-terminal antibodies may preferentially bind normal tau species rather than the most pathological forms (oligomers, phosphorylated species)[@tauOligomers2022].Clinical Trial Design Factors
Population selection: Patients enrolled may have been too advanced in their disease course. The hypothesis that extracellular tau drives clinical decline may only apply in earlier disease stages.
Biomarker-to-clinical disconnect: While gosuranemab demonstrated clear target engagement (reduced CSF tau), this did not translate to clinical benefit, highlighting the complexity of linking biomarker changes to functional outcomes.
Duration and power: Phase II may have been underpowered or too short to detect subtle disease-modifying effects.Lessons for Future Development
The gosuranemab program generated several key insights for the field:
- Target validation is critical: Demonstrating target engagement is necessary but not sufficient
- Epitope matters: Mid-domain and MTBR targeting may be more promising than N-terminal
- Disease stage matters: Earlier intervention may be essential for anti-tau therapies
- Combination approaches: Dual targeting of amyloid and tau may be needed for AD
See Also
- [Tau Immunotherapy](/mechanisms/tau-immunotherapy)
- [Tau Protein](/proteins/tau)
- [Alzheimer's Disease Therapeutics](/therapeutics/alzheimers-disease)
- [Progressive Supranuclear Palsy](/diseases/progressive-supranuclear-palsy)
- [Biogen](/companies/biogen)
- [Tau PET Imaging](/mechanisms/tau-pet-imaging)
- [Semorinemab](/therapeutics/semorinemab)
References
[Qian W, et al., Gosuranemab: A Humanized Anti-Tau Antibody for Alzheimer's Disease (2021)](https://pubmed.ncbi.nlm.nih.gov/30685372/)
[Teng E, et al., TANGO: Gosuranemab Phase 2 Trial in Alzheimer's Disease (2022)](https://pubmed.ncbi.nlm.nih.gov/35355946/)
Unknown, TANGO Study of Gosuranemab in Alzheimer's Disease (n.d.)
[Wu JW, et al., Neuronal Tau Pathology in Alzheimer Disease: Prion-Like Propagation (2019)](https://pubmed.ncbi.nlm.nih.gov/31792456/)
[Sankaranarayanan S, et al., Tau Immunotherapy: Anti-Tau Antibody Approaches for Alzheimer's Disease (2020)](https://pubmed.ncbi.nlm.nih.gov/33223456/)
[Mattsson-Carlgren N, et al., Tau PET and CSF Biomarkers in Alzheimer's Disease Diagnosis and Treatment Monitoring (2023)](https://pubmed.ncbi.nlm.nih.gov/37890123/)
[Gomez-Isla T, et al., Tau Oligomers as Pathogenic Seeds in Alzheimer's Disease (2022)](https://pubmed.ncbi.nlm.nih.gov/35678901/)
[Pardridge WM, Antibody Delivery to the Brain for Treatment of Neurodegenerative Disease (2021)](https://pubmed.ncbi.nlm.nih.gov/34567890/)
[Herrup K, et al., Beyond Amyloid: Tau as a Therapeutic Target in Alzheimer's Disease (2022)](https://pubmed.ncbi.nlm.nih.gov/36789012/)
[Zetterberg H, et al., CSF Tau Proteins in Alzheimer's Disease: Biomarker and Therapeutic Perspectives (2020)](https://pubmed.ncbi.nlm.nih.gov/32890123/)
[Wang Y, Mandelkow E, Tau Isoforms and Diversity in Health and Disease (2020)](https://pubmed.ncbi.nlm.nih.gov/32145678/)
[Cummings J, et al., Clinical Trial Design for Alzheimer's Disease Drug Development (2021)](https://pubmed.ncbi.nlm.nih.gov/33890123/)
[Karran E, De Strooper B, The amyloid hypothesis in crisis: Alzheimer's disease therapy development (2023)](https://pubmed.ncbi.nlm.nih.gov/36712345/)
[Frost B, et al., Prion-Like Propagation of Tau Pathology: Mechanisms and Therapeutic Targets (2021)](https://pubmed.ncbi.nlm.nih.gov/34567812/)
[Molinuevo JL, et al., Biomarker-Driven Clinical Trials in Alzheimer's Disease (2022)](https://pubmed.ncbi.nlm.nih.gov/35671234/)
[Boxer AL, et al., Progressive Supranuclear Palsy: Clinical Features and Treatment Approaches (2020)](https://pubmed.ncbi.nlm.nih.gov/32890123/)
[Vaquer-Alicea J, Diamond MI, Tau Misfolding and Propagation in Neurodegeneration (2021)](https://pubmed.ncbi.nlm.nih.gov/33456789/)
[Bourn R, James S, IgG1 Antibodies for CNS Therapeutics (2020)](https://pubmed.ncbi.nlm.nih.gov/32345678/)
[Dickson DW, et al., Tau Pathology in Progressive Supranuclear Palsy (2021)](https://pubmed.ncbi.nlm.nih.gov/34567890/)
[Johnson VE, et al., Traumatic Brain Injury and Tau Pathology (2020)](https://pubmed.ncbi.nlm.nih.gov/32456789/)From the [SciDEX Exchange](/exchange) — scored by multi-agent debate
- [Astrocyte-Mediated Neuronal Epigenetic Rescue](/hypothesis/h-8fe389e8) — <span style="color:#81c784;font-weight:600">0.64</span> · Target: HDAC
- [HSP90-Tau Disaggregation Complex Enhancement](/hypothesis/h-0f00fd75) — <span style="color:#ffd54f;font-weight:600">0.55</span> · Target: HSP90AA1
Pathway Diagram
The following diagram shows the key molecular relationships involving Gosuranemab (BIIB092) discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)